Texas Instruments LM185H-1.2/NOPB

Overview

LM185H-1.2/NOPB from Texas Instruments is a hermetically sealed, 2-terminal micropower band-gap voltage reference diode delivering a precise 1.235 V output with ±1% initial tolerance, 1 Ω dynamic impedance, and operation from 10 μA to 20 mA over −55°C to +125°C. It enables ultra-low-power analog circuitry such as portable battery-powered meters, precision thermometers, and micropower regulators where long shelf-life battery operation is critical.

For engineers reviewing the LM185H-1.2/NOPB datasheet, LM185H-1.2/NOPB pinout, LM185H-1.2/NOPB application, or LM185H-1.2/NOPB equivalent, key selection considerations include its military-grade temperature range, TO-package hermeticity, low noise (60 μV_rms), tight temperature coefficient (≤150 ppm/°C), and compatibility with capacitive loading without instability.

Technical Context

The LM185H-1.2/NOPB uses a band-gap reference architecture built solely from transistors and resistors-enabling low noise, excellent long-term stability (20 ppm/1000 hr), and minimal drift across its full −55°C to +125°C operating range. Its on-chip trimming achieves ±1% initial voltage accuracy without external calibration.

Designed for high reliability in harsh environments, it features hermetic TO packaging (NDU drawing), 2 kV HBM ESD rating, and absolute maximum reverse current of 30 mA. The device operates as a 2-terminal shunt regulator: cathode connects to supply, anode to ground or load, with regulation maintained via controlled reverse-bias current.

Key Specifications

Pinout & Package

LM185H-1.2/NOPB is supplied in a hermetic TO package (NDU drawing), rated for −55°C to +125°C operation. The package has two leads: lead 1 (anode) and lead 2 (cathode), with no internal die attach pad connection required.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shunt voltage reference applications.

Compared with LM285H-1.2/NOPB, LM185H-1.2/NOPB provides extended temperature range and hermetic reliability at modest cost premium; versus REF102CP, it offers simpler 2-terminal implementation and 100× lower operating current-critical for energy-constrained systems.

Availability

LM185H-1.2/NOPB is available at Aetrix Electronics and suitable for aerospace instrumentation, downhole oilfield sensors, and military-grade portable test equipment requiring stable component supply across extended temperature ranges and long service lifetimes.

Supply support for LM185H-1.2/NOPB includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of heritage in precision analog ICs and voltage references.

The LM185 series was designed specifically for high-reliability, wide-temperature shunt reference applications in defense, aerospace, and industrial systems where hermetic sealing and long-term stability are mandatory.

FAQ

What is the operating temperature range of the LM185H-1.2/NOPB?

The LM185H-1.2/NOPB is rated for continuous operation from −55°C to +125°C. This extended range is enabled by its hermetic TO package and internal band-gap design, making it suitable for aerospace, downhole, and military applications where ambient conditions exceed commercial-grade limits. The LM185H-1.2/NOPB maintains specified electrical performance-including ±1% initial tolerance and ≤150 ppm/°C temperature coefficient-across this full range.

Is the LM185H-1.2/NOPB a 2-terminal or 3-terminal device?

The LM185H-1.2/NOPB is a true 2-terminal shunt voltage reference: it has only an anode and cathode, with no separate reference, ground, or adjust pin. It functions like a precision Zener-connected in parallel with the load-and regulates by sinking current through its cathode. This simplifies PCB layout and eliminates external resistor networks required by 3-terminal series references. The LM185H-1.2/NOPB does not require a dedicated ground connection separate from its anode terminal.

Can the LM185H-1.2/NOPB drive capacitive loads without oscillation?

Yes-the LM185H-1.2/NOPB is explicitly designed for exceptional capacitive loading tolerance, remaining stable with output capacitances exceeding 1 μF. This is achieved through internal compensation and low dynamic impedance (1 Ω). Unlike many references that require series isolation resistors or careful layout to avoid ringing, the LM185H-1.2/NOPB can directly drive bypass caps in battery-monitoring circuits or ADC reference inputs without external stabilization components.

What is the minimum operating current for the LM185H-1.2/NOPB?

The LM185H-1.2/NOPB specifies a minimum operating current of 10 μA, verified across its full −55°C to +125°C temperature range. At this current, it maintains regulation within its 1.223–1.247 V output window and exhibits 1 Ω dynamic impedance. This ultra-low minimum current enables multi-year operation from primary lithium batteries (e.g., CR2032) in maintenance-free sensor nodes-where the LM185H-1.2/NOPB's 10 μA draw is often less than the battery's self-discharge rate.

Does the LM185H-1.2/NOPB have a hermetic package?

Yes-the LM185H-1.2/NOPB uses a hermetic TO package (package drawing NDU), confirmed by TI's packaging documentation and military-grade temperature rating (−55°C to +125°C). Hermetic sealing prevents moisture ingress and parameter drift over time, critical for long-life deployments in humid or corrosive environments. This distinguishes it from plastic-packaged variants like LM285Z-1.2/NOPB and directly supports MIL-STD-883-compliant reliability requirements.